The disclosure relates generally to a semiconductor device with a field ring or a number of field rings in an edge pattern which surrounds a central cell area and has one or more field plate discharge patterns. The semiconductor device has a semiconductor body which has in the cell area a first electrode which is electrically connected to a first near-surface zone of the semiconductor body. Furthermore, a second electrode which is electrically connected to a second zone of the semiconductor body is arranged on the rear side of the semiconductor body. Between the first and the second electrode, a drift section is arranged in the semiconductor body. The drift section material of the drift section also extends to the edge of the semiconductor body in the edge pattern. In the drift section material of the edge area, the field ring with complementary doping to the drift section is arranged which represents a protective effect for the cell area.
In such semiconductor devices, there is a risk that during a switching process in which the device changes from a non-conducting state into a conducting state, p-charge carriers, that is to say holes, cannot flow quickly enough into the floating area, with complementary doping to the drift section, of the field ring so that, for example, the horizontal field plate coupled to the field ring is capacitively pulled to a negative potential during the switching-on. This negative potential causes a depletion of charge in the drift section material until the potential of the horizontal field plates is raised again by leakage currents.
To maximize the blocking capability of a semiconductor device, a number of field rings can also be provided in each case combined with field plates and discharge patterns.